Graphite is used in large quantities in the casting of metallic articles, especially uranium fuel rods for nuclear reactors. In such use the graphite becomes contaminated with the metal being cast and is essentially scrap. It is necessary for the metal contaminant which typically forms no more than ten per cent by weight, eg 2 to 6 per cent by weight of the scrap, to be separated from the graphite so that the graphite can be safely disposed of. The metal may be recovered, and, where appropriate, re-used. One known method of separation comprises incinerating the graphite and collecting the metallic contaminant as ash. This method is expensive and it is harmful to the environment because of the large quantities of carbon dioxide produced.